[PATCH rdma-next V3 0/5] Refactor RDMA netlink infrastructure

[PATCH rdma-next V3 0/5] Refactor RDMA netlink infrastructure

[Leon Romanovsky]

The following patch set is a preparation to addition of
netlink handlers to support RDMA tool. It simplifies the code,
removes useless client infrastructure, concentrates netlink validity
checks and allows future patches to remove a lot of dead code
from iwcm* code base (all operations related to nl_clients).

It is based on already sent to the mailing list patch [1]
"Revert "IB/core: Add flow control to the portmapper netlink calls""

[1] https://patchwork.kernel.org/patch/9752865/

Changelog
v2->v3:
 * Rebase on top -rc4.
v1->v2:
 * Added Chien's ROB tags
 Patch #1:
  * Annotate max_num_ops with "static const" to calculate the value once only.

v0->v1:
 * Moved to separate topic from rdmatool.
 Patch #1:
  * Add check to catch already initialized callback table to avoid
    double registration of the same protocol.
  * Rewrite the validity check to use array instead of switch().

CC: Bart Van Assche <bart.vanassche-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org>
CC: Chien Tin Tung <chien.tin.tung-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
CC: Steve Wise <swise-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org>

Available in the "topic/betlink-refactor-v3" topic branch of this git repo:
git://git.kernel.org/pub/scm/linux/kernel/git/leon/linux-rdma.git

Or for browsing:
https://git.kernel.org/cgit/linux/kernel/git/leon/linux-rdma.git/log/?h=topic/netlink-refactor-v3

Leon Romanovsky (5):
  RDMA/netlink: Remove netlink clients infrastructure
  RDMA/netlink: Remove redundant owner option for netlink callbacks
  RDMA/netlink: Avoid double pass for RDMA netlink messages
  RDMA/iwcm: Remove useless check of nelink client validity
  RDMA/iwcm: Remove extra EXPORT_SYMBOLS

 drivers/infiniband/core/cma.c       |   9 +-
 drivers/infiniband/core/core_priv.h |   4 +-
 drivers/infiniband/core/device.c    |  41 ++----
 drivers/infiniband/core/iwcm.c      |  10 +-
 drivers/infiniband/core/iwpm_msg.c  |  12 --
 drivers/infiniband/core/iwpm_util.c |  11 --
 drivers/infiniband/core/netlink.c   | 249 +++++++++++++++++++-----------------
 include/rdma/rdma_netlink.h         |  14 +-
 8 files changed, 155 insertions(+), 195 deletions(-)

--
2.13.1

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[PATCH rdma-next V3 1/5] RDMA/netlink: Remove netlink clients infrastructure

[Leon Romanovsky]

From: Leon Romanovsky <leonro-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>

RDMA netlink has complicated infrastructure to add and remove netlink
clients to NETLINK_RDMA family. This complicates the code and not in
use because not many clients are available (3 clients) and most of them
(2 clients) are statically compiled together with netlink.c.

The following patch refactors RDMA netlink and opens door for the future
patches which will be able to get rid of a lot of dead iwcm* code.

Signed-off-by: Leon Romanovsky <leonro-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
Reviewed-by: Chien Tin Tung <chien.tin.tung-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
 drivers/infiniband/core/cma.c       |   6 +-
 drivers/infiniband/core/core_priv.h |   4 +-
 drivers/infiniband/core/device.c    |  41 ++------
 drivers/infiniband/core/iwcm.c      |  10 +-
 drivers/infiniband/core/netlink.c   | 185 +++++++++++++++++-------------------
 include/rdma/rdma_netlink.h         |  13 +--
 6 files changed, 110 insertions(+), 149 deletions(-)

diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index 31bb82d8ecd7..350aa78d08b2 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -4530,9 +4530,7 @@ static int __init cma_init(void)
 	if (ret)
 		goto err;

-	if (ibnl_add_client(RDMA_NL_RDMA_CM, ARRAY_SIZE(cma_cb_table),
-			    cma_cb_table))
-		pr_warn("RDMA CMA: failed to add netlink callback\n");
+	rdma_nl_register(RDMA_NL_RDMA_CM, cma_cb_table);
 	cma_configfs_init();

 	return 0;
@@ -4549,7 +4547,7 @@ static int __init cma_init(void)
 static void __exit cma_cleanup(void)
 {
 	cma_configfs_exit();
-	ibnl_remove_client(RDMA_NL_RDMA_CM);
+	rdma_nl_unregister(RDMA_NL_RDMA_CM);
 	ib_unregister_client(&cma_client);
 	unregister_netdevice_notifier(&cma_nb);
 	rdma_addr_unregister_client(&addr_client);
diff --git a/drivers/infiniband/core/core_priv.h b/drivers/infiniband/core/core_priv.h
index d92ab4eaa8f3..ce0f90fc7b3e 100644
--- a/drivers/infiniband/core/core_priv.h
+++ b/drivers/infiniband/core/core_priv.h
@@ -169,8 +169,8 @@ void ib_mad_cleanup(void);
 int ib_sa_init(void);
 void ib_sa_cleanup(void);

-int ibnl_init(void);
-void ibnl_cleanup(void);
+int rdma_nl_init(void);
+void rdma_nl_exit(void);

 /**
  * Check if there are any listeners to the netlink group
diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
index 81d447da0048..5c70ea49d5ad 100644
--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -1008,29 +1008,15 @@ struct net_device *ib_get_net_dev_by_params(struct ib_device *dev,
 }
 EXPORT_SYMBOL(ib_get_net_dev_by_params);

-static struct ibnl_client_cbs ibnl_ls_cb_table[] = {
+static const struct ibnl_client_cbs ibnl_ls_cb_table[] = {
 	[RDMA_NL_LS_OP_RESOLVE] = {
-		.dump = ib_nl_handle_resolve_resp,
-		.module = THIS_MODULE },
+		.dump = ib_nl_handle_resolve_resp},
 	[RDMA_NL_LS_OP_SET_TIMEOUT] = {
-		.dump = ib_nl_handle_set_timeout,
-		.module = THIS_MODULE },
+		.dump = ib_nl_handle_set_timeout},
 	[RDMA_NL_LS_OP_IP_RESOLVE] = {
-		.dump = ib_nl_handle_ip_res_resp,
-		.module = THIS_MODULE },
+		.dump = ib_nl_handle_ip_res_resp},
 };

-static int ib_add_ibnl_clients(void)
-{
-	return ibnl_add_client(RDMA_NL_LS, ARRAY_SIZE(ibnl_ls_cb_table),
-			       ibnl_ls_cb_table);
-}
-
-static void ib_remove_ibnl_clients(void)
-{
-	ibnl_remove_client(RDMA_NL_LS);
-}
-
 static int __init ib_core_init(void)
 {
 	int ret;
@@ -1052,9 +1038,9 @@ static int __init ib_core_init(void)
 		goto err_comp;
 	}

-	ret = ibnl_init();
+	ret = rdma_nl_init();
 	if (ret) {
-		pr_warn("Couldn't init IB netlink interface\n");
+		pr_warn("Couldn't init IB netlink interface %d\n", ret);
 		goto err_sysfs;
 	}

@@ -1076,24 +1062,17 @@ static int __init ib_core_init(void)
 		goto err_mad;
 	}

-	ret = ib_add_ibnl_clients();
-	if (ret) {
-		pr_warn("Couldn't register ibnl clients\n");
-		goto err_sa;
-	}
-
+	rdma_nl_register(RDMA_NL_LS, ibnl_ls_cb_table);
 	ib_cache_setup();

 	return 0;

-err_sa:
-	ib_sa_cleanup();
 err_mad:
 	ib_mad_cleanup();
 err_addr:
 	addr_cleanup();
 err_ibnl:
-	ibnl_cleanup();
+	rdma_nl_exit();
 err_sysfs:
 	class_unregister(&ib_class);
 err_comp:
@@ -1106,11 +1085,11 @@ static int __init ib_core_init(void)
 static void __exit ib_core_cleanup(void)
 {
 	ib_cache_cleanup();
-	ib_remove_ibnl_clients();
+	rdma_nl_unregister(RDMA_NL_LS);
 	ib_sa_cleanup();
 	ib_mad_cleanup();
 	addr_cleanup();
-	ibnl_cleanup();
+	rdma_nl_exit();
 	class_unregister(&ib_class);
 	destroy_workqueue(ib_comp_wq);
 	/* Make sure that any pending umem accounting work is done. */
diff --git a/drivers/infiniband/core/iwcm.c b/drivers/infiniband/core/iwcm.c
index 31661b5c1743..8599271d8be6 100644
--- a/drivers/infiniband/core/iwcm.c
+++ b/drivers/infiniband/core/iwcm.c
@@ -1175,12 +1175,8 @@ static int __init iw_cm_init(void)
 	ret = iwpm_init(RDMA_NL_IWCM);
 	if (ret)
 		pr_err("iw_cm: couldn't init iwpm\n");
-
-	ret = ibnl_add_client(RDMA_NL_IWCM, ARRAY_SIZE(iwcm_nl_cb_table),
-			      iwcm_nl_cb_table);
-	if (ret)
-		pr_err("iw_cm: couldn't register netlink callbacks\n");
-
+	else
+		rdma_nl_register(RDMA_NL_IWCM, iwcm_nl_cb_table);
 	iwcm_wq = alloc_ordered_workqueue("iw_cm_wq", WQ_MEM_RECLAIM);
 	if (!iwcm_wq)
 		return -ENOMEM;
@@ -1200,7 +1196,7 @@ static void __exit iw_cm_cleanup(void)
 {
 	unregister_net_sysctl_table(iwcm_ctl_table_hdr);
 	destroy_workqueue(iwcm_wq);
-	ibnl_remove_client(RDMA_NL_IWCM);
+	rdma_nl_unregister(RDMA_NL_IWCM);
 	iwpm_exit(RDMA_NL_IWCM);
 }

diff --git a/drivers/infiniband/core/netlink.c b/drivers/infiniband/core/netlink.c
index 454d51e432db..31f4d33149bc 100644
--- a/drivers/infiniband/core/netlink.c
+++ b/drivers/infiniband/core/netlink.c
@@ -39,16 +39,13 @@
 #include <rdma/rdma_netlink.h>
 #include "core_priv.h"

-struct ibnl_client {
-	struct list_head		list;
-	int				index;
-	int				nops;
-	const struct ibnl_client_cbs   *cb_table;
-};
+#include "core_priv.h"

-static DEFINE_MUTEX(ibnl_mutex);
+static DEFINE_MUTEX(rdma_nl_mutex);
 static struct sock *nls;
-static LIST_HEAD(client_list);
+static struct {
+	const struct ibnl_client_cbs   *cb_table;
+} rdma_nl_types[RDMA_NL_NUM_CLIENTS];

 int ibnl_chk_listeners(unsigned int group)
 {
@@ -57,58 +54,74 @@ int ibnl_chk_listeners(unsigned int group)
 	return 0;
 }

-int ibnl_add_client(int index, int nops,
-		    const struct ibnl_client_cbs cb_table[])
+static bool is_nl_msg_valid(unsigned int type, unsigned int op)
 {
-	struct ibnl_client *cur;
-	struct ibnl_client *nl_client;
+	static const unsigned int max_num_ops[RDMA_NL_NUM_CLIENTS - 1] = {
+				  RDMA_NL_RDMA_CM_NUM_OPS,
+				  RDMA_NL_IWPM_NUM_OPS,
+				  0,
+				  RDMA_NL_LS_NUM_OPS,
+				  0 };

-	nl_client = kmalloc(sizeof *nl_client, GFP_KERNEL);
-	if (!nl_client)
-		return -ENOMEM;
+	/*
+	 * This BUILD_BUG_ON is intended to catch addition of new
+	 * RDMA netlink protocol without updating the array above.
+	 */
+	BUILD_BUG_ON(RDMA_NL_NUM_CLIENTS != 6);

-	nl_client->index	= index;
-	nl_client->nops		= nops;
-	nl_client->cb_table	= cb_table;
+	if (type > RDMA_NL_NUM_CLIENTS - 1)
+		return false;

-	mutex_lock(&ibnl_mutex);
+	return (op < max_num_ops[type - 1]) ? true : false;
+}

-	list_for_each_entry(cur, &client_list, list) {
-		if (cur->index == index) {
-			pr_warn("Client for %d already exists\n", index);
-			mutex_unlock(&ibnl_mutex);
-			kfree(nl_client);
-			return -EINVAL;
-		}
-	}
+static bool is_nl_valid(unsigned int type, unsigned int op)
+{
+	if (!is_nl_msg_valid(type, op) ||
+	    !rdma_nl_types[type].cb_table ||
+	    !rdma_nl_types[type].cb_table[op].dump)
+		return false;
+	return true;
+}

-	list_add_tail(&nl_client->list, &client_list);
+void rdma_nl_register(unsigned int index,
+		      const struct ibnl_client_cbs cb_table[])
+{
+	mutex_lock(&rdma_nl_mutex);
+	if (!is_nl_msg_valid(index, 0)) {
+		/*
+		 * All clients are not interesting in success/failure of
+		 * this call. They want to see the print to error log and
+		 * continue their initialization. Print warning for them,
+		 * because it is programmer's error to be here.
+		 */
+		mutex_unlock(&rdma_nl_mutex);
+		WARN(true,
+		     "The not-valid %u index was supplied to RDMA netlink\n",
+		     index);
+		return;
+	}

-	mutex_unlock(&ibnl_mutex);
+	if (rdma_nl_types[index].cb_table) {
+		mutex_unlock(&rdma_nl_mutex);
+		WARN(true,
+		     "The %u index is already registered in RDMA netlink\n",
+		     index);
+		return;
+	}

-	return 0;
+	rdma_nl_types[index].cb_table = cb_table;
+	mutex_unlock(&rdma_nl_mutex);
 }
-EXPORT_SYMBOL(ibnl_add_client);
+EXPORT_SYMBOL(rdma_nl_register);

-int ibnl_remove_client(int index)
+void rdma_nl_unregister(unsigned int index)
 {
-	struct ibnl_client *cur, *next;
-
-	mutex_lock(&ibnl_mutex);
-	list_for_each_entry_safe(cur, next, &client_list, list) {
-		if (cur->index == index) {
-			list_del(&(cur->list));
-			mutex_unlock(&ibnl_mutex);
-			kfree(cur);
-			return 0;
-		}
-	}
-	pr_warn("Can't remove callback for client idx %d. Not found\n", index);
-	mutex_unlock(&ibnl_mutex);
-
-	return -EINVAL;
+	mutex_lock(&rdma_nl_mutex);
+	rdma_nl_types[index].cb_table = NULL;
+	mutex_unlock(&rdma_nl_mutex);
 }
-EXPORT_SYMBOL(ibnl_remove_client);
+EXPORT_SYMBOL(rdma_nl_unregister);

 void *ibnl_put_msg(struct sk_buff *skb, struct nlmsghdr **nlh, int seq,
 		   int len, int client, int op, int flags)
@@ -149,45 +162,31 @@ EXPORT_SYMBOL(ibnl_put_attr);
 static int ibnl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
 			struct netlink_ext_ack *extack)
 {
-	struct ibnl_client *client;
 	int type = nlh->nlmsg_type;
-	int index = RDMA_NL_GET_CLIENT(type);
+	unsigned int index = RDMA_NL_GET_CLIENT(type);
 	unsigned int op = RDMA_NL_GET_OP(type);
+	struct netlink_callback cb = {};
+	struct netlink_dump_control c = {};

-	list_for_each_entry(client, &client_list, list) {
-		if (client->index == index) {
-			if (op >= client->nops || !client->cb_table[op].dump)
-				return -EINVAL;
-
-			/*
-			 * For response or local service set_timeout request,
-			 * there is no need to use netlink_dump_start.
-			 */
-			if (!(nlh->nlmsg_flags & NLM_F_REQUEST) ||
-			    (index == RDMA_NL_LS &&
-			     op == RDMA_NL_LS_OP_SET_TIMEOUT)) {
-				struct netlink_callback cb = {
-					.skb = skb,
-					.nlh = nlh,
-					.dump = client->cb_table[op].dump,
-					.module = client->cb_table[op].module,
-				};
-
-				return cb.dump(skb, &cb);
-			}
-
-			{
-				struct netlink_dump_control c = {
-					.dump = client->cb_table[op].dump,
-					.module = client->cb_table[op].module,
-				};
-				return netlink_dump_start(nls, skb, nlh, &c);
-			}
-		}
+	if (!is_nl_valid(index, op))
+		return -EINVAL;
+
+	/*
+	 * For response or local service set_timeout request,
+	 * there is no need to use netlink_dump_start.
+	 */
+	if (!(nlh->nlmsg_flags & NLM_F_REQUEST) ||
+	    (index == RDMA_NL_LS && op == RDMA_NL_LS_OP_SET_TIMEOUT)) {
+		cb.skb = skb;
+		cb.nlh = nlh;
+		cb.dump = rdma_nl_types[index].cb_table[op].dump;
+		cb.module = rdma_nl_types[index].cb_table[op].module;
+		return cb.dump(skb, &cb);
 	}

-	pr_info("Index %d wasn't found in client list\n", index);
-	return -EINVAL;
+	c.dump = rdma_nl_types[index].cb_table[op].dump;
+	c.module = rdma_nl_types[index].cb_table[op].module;
+	return netlink_dump_start(nls, skb, nlh, &c);
 }

 static void ibnl_rcv_reply_skb(struct sk_buff *skb)
@@ -221,10 +220,10 @@ static void ibnl_rcv_reply_skb(struct sk_buff *skb)

 static void ibnl_rcv(struct sk_buff *skb)
 {
-	mutex_lock(&ibnl_mutex);
+	mutex_lock(&rdma_nl_mutex);
 	ibnl_rcv_reply_skb(skb);
 	netlink_rcv_skb(skb, &ibnl_rcv_msg);
-	mutex_unlock(&ibnl_mutex);
+	mutex_unlock(&rdma_nl_mutex);
 }

 int ibnl_unicast(struct sk_buff *skb, struct nlmsghdr *nlh,
@@ -241,31 +240,25 @@ int ibnl_multicast(struct sk_buff *skb, struct nlmsghdr *nlh,
 }
 EXPORT_SYMBOL(ibnl_multicast);

-int __init ibnl_init(void)
+int __init rdma_nl_init(void)
 {
 	struct netlink_kernel_cfg cfg = {
 		.input	= ibnl_rcv,
 	};

 	nls = netlink_kernel_create(&init_net, NETLINK_RDMA, &cfg);
-	if (!nls) {
-		pr_warn("Failed to create netlink socket\n");
+	if (!nls)
 		return -ENOMEM;
-	}

 	return 0;
 }

-void ibnl_cleanup(void)
+void rdma_nl_exit(void)
 {
-	struct ibnl_client *cur, *next;
+	int idx;

-	mutex_lock(&ibnl_mutex);
-	list_for_each_entry_safe(cur, next, &client_list, list) {
-		list_del(&(cur->list));
-		kfree(cur);
-	}
-	mutex_unlock(&ibnl_mutex);
+	for (idx = 0; idx < RDMA_NL_NUM_CLIENTS; idx++)
+		rdma_nl_unregister(idx);

 	netlink_kernel_release(nls);
 }
diff --git a/include/rdma/rdma_netlink.h b/include/rdma/rdma_netlink.h
index 348c102cb5f6..162e58f118e7 100644
--- a/include/rdma/rdma_netlink.h
+++ b/include/rdma/rdma_netlink.h
@@ -11,23 +11,18 @@ struct ibnl_client_cbs {
 };

 /**
- * Add a a client to the list of IB netlink exporters.
+ * Register client in RDMA netlink.
  * @index: Index of the added client
- * @nops: Number of supported ops by the added client.
  * @cb_table: A table for op->callback
- *
- * Returns 0 on success or a negative error code.
  */
-int ibnl_add_client(int index, int nops,
-		    const struct ibnl_client_cbs cb_table[]);
+void rdma_nl_register(unsigned int index,
+		      const struct ibnl_client_cbs cb_table[]);

 /**
  * Remove a client from IB netlink.
  * @index: Index of the removed IB client.
- *
- * Returns 0 on success or a negative error code.
  */
-int ibnl_remove_client(int index);
+void rdma_nl_unregister(unsigned int index);

 /**
  * Put a new message in a supplied skb.
--
2.13.1

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[PATCH rdma-next V3 2/5] RDMA/netlink: Remove redundant owner option for netlink callbacks

[Leon Romanovsky]

From: Leon Romanovsky <leonro-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>

Owner field is not needed to be set because netlink is part of ib_core
which will be unloaded last after all other modules are unloaded.

Signed-off-by: Leon Romanovsky <leonro-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
---
 drivers/infiniband/core/cma.c     | 3 +--
 drivers/infiniband/core/netlink.c | 2 --
 include/rdma/rdma_netlink.h       | 1 -
 3 files changed, 1 insertion(+), 5 deletions(-)

diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index 350aa78d08b2..e0189a130014 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -4477,8 +4477,7 @@ static int cma_get_id_stats(struct sk_buff *skb, struct netlink_callback *cb)
 }

 static const struct ibnl_client_cbs cma_cb_table[] = {
-	[RDMA_NL_RDMA_CM_ID_STATS] = { .dump = cma_get_id_stats,
-				       .module = THIS_MODULE },
+	[RDMA_NL_RDMA_CM_ID_STATS] = { .dump = cma_get_id_stats},
 };

 static int cma_init_net(struct net *net)
diff --git a/drivers/infiniband/core/netlink.c b/drivers/infiniband/core/netlink.c
index 31f4d33149bc..6cb534a595ea 100644
--- a/drivers/infiniband/core/netlink.c
+++ b/drivers/infiniband/core/netlink.c
@@ -180,12 +180,10 @@ static int ibnl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
 		cb.skb = skb;
 		cb.nlh = nlh;
 		cb.dump = rdma_nl_types[index].cb_table[op].dump;
-		cb.module = rdma_nl_types[index].cb_table[op].module;
 		return cb.dump(skb, &cb);
 	}

 	c.dump = rdma_nl_types[index].cb_table[op].dump;
-	c.module = rdma_nl_types[index].cb_table[op].module;
 	return netlink_dump_start(nls, skb, nlh, &c);
 }

diff --git a/include/rdma/rdma_netlink.h b/include/rdma/rdma_netlink.h
index 162e58f118e7..7690aaabb958 100644
--- a/include/rdma/rdma_netlink.h
+++ b/include/rdma/rdma_netlink.h
@@ -7,7 +7,6 @@

 struct ibnl_client_cbs {
 	int (*dump)(struct sk_buff *skb, struct netlink_callback *nlcb);
-	struct module *module;
 };

 /**
--
2.13.1

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[PATCH rdma-next V3 3/5] RDMA/netlink: Avoid double pass for RDMA netlink messages

[Leon Romanovsky]

From: Leon Romanovsky <leonro-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>

The standard netlink_rcv_skb function skips messages without
NLM_F_REQUEST flag in it, while SA netlink client issues them.

In commit bc10ed7d3d19 ("IB/core: Add rdma netlink helper functions")
the local function was introduced to allow such messages.

This led to double pass for every incoming message.

In this patch, we unify that local implementation and netlink_rcv_skb
functions, so there will be no need for double pass anymore.

As a outcome, this combined function gained more strict check
for NLM_F_REQUEST flag and it is now allowed for SA pathquery
client only.

Signed-off-by: Leon Romanovsky <leonro-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
---
 drivers/infiniband/core/netlink.c | 62 +++++++++++++++++++++++++++------------
 1 file changed, 44 insertions(+), 18 deletions(-)

diff --git a/drivers/infiniband/core/netlink.c b/drivers/infiniband/core/netlink.c
index 6cb534a595ea..86337d5e7551 100644
--- a/drivers/infiniband/core/netlink.c
+++ b/drivers/infiniband/core/netlink.c
@@ -159,8 +159,8 @@ int ibnl_put_attr(struct sk_buff *skb, struct nlmsghdr *nlh,
 }
 EXPORT_SYMBOL(ibnl_put_attr);

-static int ibnl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
-			struct netlink_ext_ack *extack)
+static int rdma_nl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
+			   struct netlink_ext_ack *extack)
 {
 	int type = nlh->nlmsg_type;
 	unsigned int index = RDMA_NL_GET_CLIENT(type);
@@ -187,40 +187,66 @@ static int ibnl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
 	return netlink_dump_start(nls, skb, nlh, &c);
 }

-static void ibnl_rcv_reply_skb(struct sk_buff *skb)
+/*
+ * This function is similar to netlink_rcv_skb with one exception:
+ * It calls to the callback for the netlink messages without NLM_F_REQUEST
+ * flag. These messages are intended for RDMA_NL_LS consumer, so it is allowed
+ * for that consumer only.
+ */
+static int rdma_nl_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *,
+						   struct nlmsghdr *,
+						   struct netlink_ext_ack *))
 {
+	struct netlink_ext_ack extack = {};
 	struct nlmsghdr *nlh;
-	int msglen;
+	int err;

-	/*
-	 * Process responses until there is no more message or the first
-	 * request. Generally speaking, it is not recommended to mix responses
-	 * with requests.
-	 */
 	while (skb->len >= nlmsg_total_size(0)) {
+		int msglen;
+
 		nlh = nlmsg_hdr(skb);
+		err = 0;

 		if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len)
-			return;
+			return 0;

-		/* Handle response only */
-		if (nlh->nlmsg_flags & NLM_F_REQUEST)
-			return;
+		/*
+		 * Generally speaking, the only requests are handled
+		 * by the kernel, but RDMA_NL_LS is different, because it
+		 * runs backward netlink scheme. Kernel initiates messages
+		 * and waits for reply with data to keep pathrecord cache
+		 * in sync.
+		 */
+		if (!(nlh->nlmsg_flags & NLM_F_REQUEST) &&
+		    (RDMA_NL_GET_CLIENT(nlh->nlmsg_type) != RDMA_NL_LS))
+			goto ack;
+
+		/* Skip control messages */
+		if (nlh->nlmsg_type < NLMSG_MIN_TYPE)
+			goto ack;
+
+		err = cb(skb, nlh, &extack);
+		if (err == -EINTR)
+			goto skip;

-		ibnl_rcv_msg(skb, nlh, NULL);
+ack:
+		if (nlh->nlmsg_flags & NLM_F_ACK || err)
+			netlink_ack(skb, nlh, err, &extack);

+skip:
 		msglen = NLMSG_ALIGN(nlh->nlmsg_len);
 		if (msglen > skb->len)
 			msglen = skb->len;
 		skb_pull(skb, msglen);
 	}
+
+	return 0;
 }

-static void ibnl_rcv(struct sk_buff *skb)
+static void rdma_nl_rcv(struct sk_buff *skb)
 {
 	mutex_lock(&rdma_nl_mutex);
-	ibnl_rcv_reply_skb(skb);
-	netlink_rcv_skb(skb, &ibnl_rcv_msg);
+	rdma_nl_rcv_skb(skb, &rdma_nl_rcv_msg);
 	mutex_unlock(&rdma_nl_mutex);
 }

@@ -241,7 +267,7 @@ EXPORT_SYMBOL(ibnl_multicast);
 int __init rdma_nl_init(void)
 {
 	struct netlink_kernel_cfg cfg = {
-		.input	= ibnl_rcv,
+		.input	= rdma_nl_rcv,
 	};

 	nls = netlink_kernel_create(&init_net, NETLINK_RDMA, &cfg);
--
2.13.1

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[PATCH rdma-next V3 4/5] RDMA/iwcm: Remove useless check of nelink client validity

[Leon Romanovsky]

From: Leon Romanovsky <leonro-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>

RDMA netlink implementation guarantees that supplied
client number is in allowed range.

Signed-off-by: Leon Romanovsky <leonro-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
Reviewed-by: Chien Tin Tung <chien.tin.tung-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
 drivers/infiniband/core/iwpm_util.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/drivers/infiniband/core/iwpm_util.c b/drivers/infiniband/core/iwpm_util.c
index f13870e69ccd..32ca2aaa4e3b 100644
--- a/drivers/infiniband/core/iwpm_util.c
+++ b/drivers/infiniband/core/iwpm_util.c
@@ -54,8 +54,6 @@ static struct iwpm_admin_data iwpm_admin;
 int iwpm_init(u8 nl_client)
 {
 	int ret = 0;
-	if (iwpm_valid_client(nl_client))
-		return -EINVAL;
 	mutex_lock(&iwpm_admin_lock);
 	if (atomic_read(&iwpm_admin.refcount) == 0) {
 		iwpm_hash_bucket = kzalloc(IWPM_MAPINFO_HASH_SIZE *
@@ -383,15 +381,11 @@ int iwpm_get_nlmsg_seq(void)

 int iwpm_valid_client(u8 nl_client)
 {
-	if (nl_client >= RDMA_NL_NUM_CLIENTS)
-		return 0;
 	return iwpm_admin.client_list[nl_client];
 }

 void iwpm_set_valid(u8 nl_client, int valid)
 {
-	if (nl_client >= RDMA_NL_NUM_CLIENTS)
-		return;
 	iwpm_admin.client_list[nl_client] = valid;
 }

--
2.13.1

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[PATCH rdma-next V3 5/5] RDMA/iwcm: Remove extra EXPORT_SYMBOLS

[Leon Romanovsky]

From: Leon Romanovsky <leonro-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>

The iwcm exports functions which are not used outside of ib_core.
This patch simply removes these EXPORT_SYMBOLS.

Signed-off-by: Leon Romanovsky <leonro-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
Reviewed-by: Chien Tin Tung <chien.tin.tung-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
 drivers/infiniband/core/iwpm_msg.c  | 12 ------------
 drivers/infiniband/core/iwpm_util.c |  5 -----
 2 files changed, 17 deletions(-)

diff --git a/drivers/infiniband/core/iwpm_msg.c b/drivers/infiniband/core/iwpm_msg.c
index a0e7c16d8bd8..1fab707b1f68 100644
--- a/drivers/infiniband/core/iwpm_msg.c
+++ b/drivers/infiniband/core/iwpm_msg.c
@@ -42,7 +42,6 @@ int iwpm_valid_pid(void)
 {
 	return iwpm_user_pid > 0;
 }
-EXPORT_SYMBOL(iwpm_valid_pid);

 /*
  * iwpm_register_pid - Send a netlink query to user space
@@ -122,7 +121,6 @@ int iwpm_register_pid(struct iwpm_dev_data *pm_msg, u8 nl_client)
 		iwpm_free_nlmsg_request(&nlmsg_request->kref);
 	return ret;
 }
-EXPORT_SYMBOL(iwpm_register_pid);

 /*
  * iwpm_add_mapping - Send a netlink add mapping message
@@ -191,7 +189,6 @@ int iwpm_add_mapping(struct iwpm_sa_data *pm_msg, u8 nl_client)
 		iwpm_free_nlmsg_request(&nlmsg_request->kref);
 	return ret;
 }
-EXPORT_SYMBOL(iwpm_add_mapping);

 /*
  * iwpm_add_and_query_mapping - Send a netlink add and query
@@ -267,7 +264,6 @@ int iwpm_add_and_query_mapping(struct iwpm_sa_data *pm_msg, u8 nl_client)
 		iwpm_free_nlmsg_request(&nlmsg_request->kref);
 	return ret;
 }
-EXPORT_SYMBOL(iwpm_add_and_query_mapping);

 /*
  * iwpm_remove_mapping - Send a netlink remove mapping message
@@ -328,7 +324,6 @@ int iwpm_remove_mapping(struct sockaddr_storage *local_addr, u8 nl_client)
 		dev_kfree_skb_any(skb);
 	return ret;
 }
-EXPORT_SYMBOL(iwpm_remove_mapping);

 /* netlink attribute policy for the received response to register pid request */
 static const struct nla_policy resp_reg_policy[IWPM_NLA_RREG_PID_MAX] = {
@@ -397,7 +392,6 @@ int iwpm_register_pid_cb(struct sk_buff *skb, struct netlink_callback *cb)
 	up(&nlmsg_request->sem);
 	return 0;
 }
-EXPORT_SYMBOL(iwpm_register_pid_cb);

 /* netlink attribute policy for the received response to add mapping request */
 static const struct nla_policy resp_add_policy[IWPM_NLA_RMANAGE_MAPPING_MAX] = {
@@ -466,7 +460,6 @@ int iwpm_add_mapping_cb(struct sk_buff *skb, struct netlink_callback *cb)
 	up(&nlmsg_request->sem);
 	return 0;
 }
-EXPORT_SYMBOL(iwpm_add_mapping_cb);

 /* netlink attribute policy for the response to add and query mapping request
  * and response with remote address info */
@@ -558,7 +551,6 @@ int iwpm_add_and_query_mapping_cb(struct sk_buff *skb,
 	up(&nlmsg_request->sem);
 	return 0;
 }
-EXPORT_SYMBOL(iwpm_add_and_query_mapping_cb);

 /*
  * iwpm_remote_info_cb - Process a port mapper message, containing
@@ -627,7 +619,6 @@ int iwpm_remote_info_cb(struct sk_buff *skb, struct netlink_callback *cb)
 			"remote_info: Mapped remote sockaddr:");
 	return ret;
 }
-EXPORT_SYMBOL(iwpm_remote_info_cb);

 /* netlink attribute policy for the received request for mapping info */
 static const struct nla_policy resp_mapinfo_policy[IWPM_NLA_MAPINFO_REQ_MAX] = {
@@ -677,7 +668,6 @@ int iwpm_mapping_info_cb(struct sk_buff *skb, struct netlink_callback *cb)
 	ret = iwpm_send_mapinfo(nl_client, iwpm_user_pid);
 	return ret;
 }
-EXPORT_SYMBOL(iwpm_mapping_info_cb);

 /* netlink attribute policy for the received mapping info ack */
 static const struct nla_policy ack_mapinfo_policy[IWPM_NLA_MAPINFO_NUM_MAX] = {
@@ -707,7 +697,6 @@ int iwpm_ack_mapping_info_cb(struct sk_buff *skb, struct netlink_callback *cb)
 	atomic_set(&echo_nlmsg_seq, cb->nlh->nlmsg_seq);
 	return 0;
 }
-EXPORT_SYMBOL(iwpm_ack_mapping_info_cb);

 /* netlink attribute policy for the received port mapper error message */
 static const struct nla_policy map_error_policy[IWPM_NLA_ERR_MAX] = {
@@ -751,4 +740,3 @@ int iwpm_mapping_error_cb(struct sk_buff *skb, struct netlink_callback *cb)
 	up(&nlmsg_request->sem);
 	return 0;
 }
-EXPORT_SYMBOL(iwpm_mapping_error_cb);
diff --git a/drivers/infiniband/core/iwpm_util.c b/drivers/infiniband/core/iwpm_util.c
index 32ca2aaa4e3b..c46442ac71a2 100644
--- a/drivers/infiniband/core/iwpm_util.c
+++ b/drivers/infiniband/core/iwpm_util.c
@@ -81,7 +81,6 @@ int iwpm_init(u8 nl_client)
 	}
 	return ret;
 }
-EXPORT_SYMBOL(iwpm_init);

 static void free_hash_bucket(void);
 static void free_reminfo_bucket(void);
@@ -107,7 +106,6 @@ int iwpm_exit(u8 nl_client)
 	iwpm_set_registration(nl_client, IWPM_REG_UNDEF);
 	return 0;
 }
-EXPORT_SYMBOL(iwpm_exit);

 static struct hlist_head *get_mapinfo_hash_bucket(struct sockaddr_storage *,
 					       struct sockaddr_storage *);
@@ -146,7 +144,6 @@ int iwpm_create_mapinfo(struct sockaddr_storage *local_sockaddr,
 	spin_unlock_irqrestore(&iwpm_mapinfo_lock, flags);
 	return ret;
 }
-EXPORT_SYMBOL(iwpm_create_mapinfo);

 int iwpm_remove_mapinfo(struct sockaddr_storage *local_sockaddr,
 			struct sockaddr_storage *mapped_local_addr)
@@ -182,7 +179,6 @@ int iwpm_remove_mapinfo(struct sockaddr_storage *local_sockaddr,
 	spin_unlock_irqrestore(&iwpm_mapinfo_lock, flags);
 	return ret;
 }
-EXPORT_SYMBOL(iwpm_remove_mapinfo);

 static void free_hash_bucket(void)
 {
@@ -295,7 +291,6 @@ int iwpm_get_remote_info(struct sockaddr_storage *mapped_loc_addr,
 	spin_unlock_irqrestore(&iwpm_reminfo_lock, flags);
 	return ret;
 }
-EXPORT_SYMBOL(iwpm_get_remote_info);

 struct iwpm_nlmsg_request *iwpm_get_nlmsg_request(__u32 nlmsg_seq,
 					u8 nl_client, gfp_t gfp)
--
2.13.1

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Re: [PATCH rdma-next V3 1/5] RDMA/netlink: Remove netlink clients infrastructure

[Dennis Dalessandro]

On 6/27/2017 1:00 AM, Leon Romanovsky wrote:
> From: Leon Romanovsky <leonro-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
> 
> RDMA netlink has complicated infrastructure to add and remove netlink
> clients to NETLINK_RDMA family. This complicates the code and not in
> use because not many clients are available (3 clients) and most of them
> (2 clients) are statically compiled together with netlink.c.

So here you say there are three clients.

> -	struct ibnl_client *cur;
> -	struct ibnl_client *nl_client;
> +	static const unsigned int max_num_ops[RDMA_NL_NUM_CLIENTS - 1] = {
> +				  RDMA_NL_RDMA_CM_NUM_OPS,
> +				  RDMA_NL_IWPM_NUM_OPS,
> +				  0,
> +				  RDMA_NL_LS_NUM_OPS,
> +				  0 };
> 
> -	nl_client = kmalloc(sizeof *nl_client, GFP_KERNEL);
> -	if (!nl_client)
> -		return -ENOMEM;
> +	/*
> +	 * This BUILD_BUG_ON is intended to catch addition of new
> +	 * RDMA netlink protocol without updating the array above.
> +	 */
> +	BUILD_BUG_ON(RDMA_NL_NUM_CLIENTS != 6);

Yet we are checking for 6? Can you elaborate here.

-Denny
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Re: [PATCH rdma-next V3 2/5] RDMA/netlink: Remove redundant owner option for netlink callbacks

[Dennis Dalessandro]

On 6/27/2017 1:00 AM, Leon Romanovsky wrote:
> From: Leon Romanovsky <leonro-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
> 
> Owner field is not needed to be set because netlink is part of ib_core
> which will be unloaded last after all other modules are unloaded.

Perhaps move the similar parts from first patch here or just squash this 
with the first?

-Denny
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Re: [PATCH rdma-next V3 1/5] RDMA/netlink: Remove netlink clients infrastructure

[Leon Romanovsky]

[-- Attachment #1: Type: text/plain, Size: 2001 bytes --]

On Mon, Jul 17, 2017 at 10:02:07AM -0400, Dennis Dalessandro wrote:
> On 6/27/2017 1:00 AM, Leon Romanovsky wrote:
> > From: Leon Romanovsky <leonro-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
> >
> > RDMA netlink has complicated infrastructure to add and remove netlink
> > clients to NETLINK_RDMA family. This complicates the code and not in
> > use because not many clients are available (3 clients) and most of them
> > (2 clients) are statically compiled together with netlink.c.
>
> So here you say there are three clients.
>
> > -	struct ibnl_client *cur;
> > -	struct ibnl_client *nl_client;
> > +	static const unsigned int max_num_ops[RDMA_NL_NUM_CLIENTS - 1] = {
> > +				  RDMA_NL_RDMA_CM_NUM_OPS,
> > +				  RDMA_NL_IWPM_NUM_OPS,
> > +				  0,
> > +				  RDMA_NL_LS_NUM_OPS,
> > +				  0 };
> >
> > -	nl_client = kmalloc(sizeof *nl_client, GFP_KERNEL);
> > -	if (!nl_client)
> > -		return -ENOMEM;
> > +	/*
> > +	 * This BUILD_BUG_ON is intended to catch addition of new
> > +	 * RDMA netlink protocol without updating the array above.
> > +	 */
> > +	BUILD_BUG_ON(RDMA_NL_NUM_CLIENTS != 6);
>
> Yet we are checking for 6? Can you elaborate here.

This check is needed to ensure that the array is properly initialized.

The clients were exposed in include/uapi/rdma/rdma_netlink.h, in the
following enum:

  6 enum {
  7         RDMA_NL_RDMA_CM = 1,
  8         RDMA_NL_IWCM,
  9         RDMA_NL_RSVD,
 10         RDMA_NL_LS,     /* RDMA Local Services */
 11         RDMA_NL_I40IW,
 12         RDMA_NL_NUM_CLIENTS
 13 };

First of all it starts from 1, second we have RDMA_NL_RSVD and
RDMA_NL_NUM_CLIENTS which exposed, but are not real clients, because
nothing is handled them

It leads for RDMA_NL_NUM_CLIENTS == 6 and this is why I'm checking for 6.

>
> -Denny
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[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]

Re: [PATCH rdma-next V3 1/5] RDMA/netlink: Remove netlink clients infrastructure

[Dennis Dalessandro]

On 7/17/2017 10:54 AM, Leon Romanovsky wrote:
> On Mon, Jul 17, 2017 at 10:02:07AM -0400, Dennis Dalessandro wrote:
>> On 6/27/2017 1:00 AM, Leon Romanovsky wrote:
>>> From: Leon Romanovsky <leonro-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
>>>
>>> RDMA netlink has complicated infrastructure to add and remove netlink
>>> clients to NETLINK_RDMA family. This complicates the code and not in
>>> use because not many clients are available (3 clients) and most of them
>>> (2 clients) are statically compiled together with netlink.c.
>>
>> So here you say there are three clients.
>>
>>> -	struct ibnl_client *cur;
>>> -	struct ibnl_client *nl_client;
>>> +	static const unsigned int max_num_ops[RDMA_NL_NUM_CLIENTS - 1] = {
>>> +				  RDMA_NL_RDMA_CM_NUM_OPS,
>>> +				  RDMA_NL_IWPM_NUM_OPS,
>>> +				  0,
>>> +				  RDMA_NL_LS_NUM_OPS,
>>> +				  0 };
>>>
>>> -	nl_client = kmalloc(sizeof *nl_client, GFP_KERNEL);
>>> -	if (!nl_client)
>>> -		return -ENOMEM;
>>> +	/*
>>> +	 * This BUILD_BUG_ON is intended to catch addition of new
>>> +	 * RDMA netlink protocol without updating the array above.
>>> +	 */
>>> +	BUILD_BUG_ON(RDMA_NL_NUM_CLIENTS != 6);
>>
>> Yet we are checking for 6? Can you elaborate here.
> 
> This check is needed to ensure that the array is properly initialized.
> 
> The clients were exposed in include/uapi/rdma/rdma_netlink.h, in the
> following enum:
> 
>    6 enum {
>    7         RDMA_NL_RDMA_CM = 1,
>    8         RDMA_NL_IWCM,
>    9         RDMA_NL_RSVD,
>   10         RDMA_NL_LS,     /* RDMA Local Services */
>   11         RDMA_NL_I40IW,
>   12         RDMA_NL_NUM_CLIENTS
>   13 };
> 
> First of all it starts from 1, second we have RDMA_NL_RSVD and
> RDMA_NL_NUM_CLIENTS which exposed, but are not real clients, because
> nothing is handled them
> 
> It leads for RDMA_NL_NUM_CLIENTS == 6 and this is why I'm checking for 6.
> 

Makes sense now.

-Denny
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